JP6464175B2 - Polarizing plate and image display device including the same - Google Patents

Description

  The present invention relates to a polarizing plate and an image display device including the same, and more specifically, a polarizing plate excellent in adhesion between a polarizer and a protective layer, excellent in heat resistance, and capable of being thinly manufactured, and The present invention relates to an image display apparatus including this.

  A polarizing plate has usually been used in a structure in which protective films are laminated on both sides of a polarizer made of a polyvinyl alcohol (hereinafter referred to as “PVA”) resin dyed with a dichroic dye or iodine. If there is no protective film, the fragile dimensional stability of the polarizer causes a problem that durability and optical properties are greatly deteriorated, and water resistance becomes extremely fragile. At this time, as the protective film, a triacetyl cellulose (TAC) film is often used because it is excellent in optical transparency and moisture permeability.

  On the other hand, with the recent development of liquid crystal display devices in mobile devices such as notebook personal computers, mobile phones, and car navigation systems, the polarizing plates constituting the liquid crystal display devices are required to be thin and light. However, with a polarizing plate in which a TAC film or the like is laminated as a protective film as described above, it is difficult to reduce the thickness of the protective film to 20 μm or less from the viewpoint of workability and durability at the time of work, and there is a limit to reducing the thickness and weight. was there.

  In order to solve the above-described problems, a technique for forming a transparent thin film layer by providing a protective film only on one side of a polarizer and applying an active energy ray-curable composition on the opposite side is proposed. Has been. On the other hand, the active energy ray-curable composition proposed to date can be classified into a radical curable composition and a cation curable composition according to a curing method. At this time, when a transparent thin film layer is formed using a cation curable composition, there is an advantage of having excellent adhesion with a polarizer, but a slow curing speed, a low curing degree, a polarizing plate generated by a dark reaction It has many drawbacks such as the curl problem.

  In order to solve such a problem, a technique for forming a transparent thin film layer using a radical curable composition containing an acrylic or acrylamide compound as a main component has been proposed. However, since the glass transition temperature of the formed transparent thin film layer is low, there is a problem that the heat resistance of the polarizing plate produced using the transparent thin film layer is not good.

  Therefore, while having a thin protective layer that can be formed by radical curing, it has excellent adhesion between the polarizer and the protective layer, maintains good adhesion even in a high humidity environment, and has a new heat resistance. There is a demand for polarizing plates.

  The present invention is for solving the above-described problem, and includes a polarizing plate excellent in adhesion between a polarizer and a protective layer even under high humidity conditions, excellent in heat resistance, and capable of being thinly manufactured. An image display device is provided.

  In one aspect, the present invention is a polarizing plate including a polarizer and a protective layer formed on at least one surface of the polarizer, and the protective layer has a hydroxyl value of 500 mg · KOH / g. A polarizing plate which is a cured product of the above radical curable composition is provided.

  On the other hand, the radically curable composition preferably contains a radically polymerizable first compound containing at least two hydroxy groups in the molecule.

  At this time, the first radical polymerizable compound may be one or more selected from the group consisting of compounds represented by Chemical Formulas 1 to 17.

  On the other hand, the radical curable composition comprises (A) a radical polymerizable first compound containing at least two hydroxy groups in the molecule, and (B) a radical polymerizable composition containing at least one hydrophilic functional group in the molecule. It may contain a second compound and (C) a radical initiator.

  At this time, the radical curable composition is (A) 5 to 90 parts by weight of a radical polymerizable first compound containing at least two hydroxy groups in the molecule with respect to 100 parts by weight of the radical curable composition; B) 5 to 90 parts by weight of a radically polymerizable second compound containing at least one hydrophilic functional group in the molecule; and (C) 0.5 to 20 parts by weight of a radical initiator are preferably included.

  On the other hand, the hydrophilic functional group of the second compound is preferably a hydroxy group.

  Specifically, the second compound may be represented by the following chemical formula I.

In Formula I, R ₁ is an ester group or an ether group; R ₂ is a C _1-10 alkyl group, a C _4-10 cycloalkyl group, or a combination thereof, wherein R ₂ Has one hydroxy substituent in the molecule; R ₃ is hydrogen or a substituted or unsubstituted C _1-10 alkyl group.

  More specifically, the radical polymerizable second compound may be one or more selected from the group consisting of compounds represented by the following chemical formulas 18 to 23.

  On the other hand, the radical curable composition further comprises (D) a polyfunctional (meth) acrylic compound and / or (E) a phosphate compound containing at least one (meth) acrylic group in the molecule. It's okay.

  At this time, in the radical curable composition, the content of the radical polymerizable first compound containing at least two hydroxy groups in the molecule (A) is 5 to 90 with respect to 100 parts by weight of the radical curable composition. Parts by weight; (B) the content of the radical polymerizable second compound containing at least one hydrophilic functional group in the molecule is 5 to 90 parts by weight; and (C) the content of the radical initiator is 0.5 to 20 parts by weight. Parts by weight; (D) the content of the polyfunctional (meth) acrylic compound is 4 to 50 parts by weight; (E) the content of the phosphate compound containing at least one (meth) acrylic group in the molecule is 0.5 It may contain ~ 30 parts by weight.

  Alternatively, the radical curable composition may further include (F) an epoxy compound having at least one epoxy group in the molecule, and (G) a cationic initiator.

  At this time, in the radical curable composition, the content of the radical polymerizable first compound containing at least two hydroxy groups in the molecule (A) is 5 to 90 with respect to 100 parts by weight of the radical curable composition. Parts by weight; (B) the content of the radical polymerizable second compound containing at least one hydrophilic functional group in the molecule is 5 to 90 parts by weight; and (C) the content of the radical initiator is 0.5 to 20 parts by weight. Parts by weight; (F) the content of the epoxy compound containing at least one epoxy group in the molecule is 1 to 30 parts by weight; (G) the content of the cation initiator is 0.5 to 15 parts by weight. It may be.

  On the other hand, the radical curable composition may be cured by photocuring or heat curing.

  On the other hand, the glass transition temperature after curing of the radical curable composition is preferably 50 ° C. or higher.

  On the other hand, the protective layer preferably has a thickness of 0.5 to 20 μm.

  On the other hand, the polarizing plate of the present invention can further adhere a protective film via an adhesive layer to the surface opposite to the surface on which the protective layer of the polarizer is formed.

  In addition, the polarizing plate of the present invention may further include an adhesive layer on the protective layer.

  In another aspect, the present invention provides an image display device including the polarizing plate.

  The polarizing plate of this invention is excellent in the adhesiveness of a polarizer and a protective layer, and can maintain this adhesiveness stably also in a high humidity condition.

  The polarizing plate of the present invention is thermally stable because it can have a high glass transition temperature through hydrogen bonds generated by a high hydroxyl value inside the cured protective layer.

  Furthermore, since the polarizing plate of the present invention has a protective layer that is thinner than a polarizing plate having a conventional transparent protective film, it can be manufactured thin.

  Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various different forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more fully explain the present invention to those having average knowledge in the art.

1. Polarizers present inventors have made extensive research, when the hydroxyl value of the curable composition for forming the protective layer is not less than 500 mg · KOH / g, adhesion between the polarizer and the protective layer The present invention has been completed by finding that the heat resistance is excellent.

  More specifically, the radical curable composition of the present invention is a polarizing plate including a polarizer and a protective layer formed on at least one surface of the polarizer, and the protective layer has a hydroxyl value (hydroxyl). (value) is a cured product of a radical curable composition of 500 mg · KOH / g or more.

1-1. Polarizer First, the polarizer of the present invention may be a polarizer well known in the art, for example, a film made of polyvinyl alcohol (PVA) containing iodine or a dichroic dye. The polarizer can be manufactured by dyeing a polyvinyl alcohol film with iodine or a dichroic dye, but the manufacturing method is not particularly limited. In this specification, a polarizer means a state not including a protective layer (or protective film), and a polarizing plate means a state including a polarizer and a protective layer (or protective film).

  On the other hand, when the polarizer is a polyvinyl alcohol film, the polyvinyl alcohol film can be used without any particular limitation as long as it contains a polyvinyl alcohol resin or a derivative thereof. At this time, examples of the derivative of the polyvinyl alcohol resin include, but are not limited to, a polyvinyl formal resin and a polyvinyl acetal resin. Alternatively, the polyvinyl alcohol-based film may be a commercially available polyvinyl alcohol-based film generally used for manufacturing a polarizer in the technical field, such as Kuraray P30, PE30, PE60, Nippon Synthetic M3000, M6000, and the like. Can also be used.

  On the other hand, the polyvinyl alcohol film is not limited to this, but the degree of polymerization is about 1,000 to 10,000, preferably about 1,500 to 5,000. This is because when the degree of polymerization satisfies the above range, the molecules can move freely and can be mixed flexibly with iodine or a dichroic dye.

1-2. Next, the protective layer of the present invention is formed using a radical curable composition to support and protect the polarizer, and the radical curable composition according to the present invention includes: The hydroxyl value is 500 mg · KOH / g or more, for example, preferably 500 to 900 mg · KOH / g, more preferably about 500 to 850 mg · KOH / g. When the hydroxyl value of the radical curable composition is high as described above, the protective layer formed using the radical curable composition maintains stable and high adhesion with the polarizer even in a relatively high humidity condition. The adhesive strength cured by such a high hydroxyl value has a strong bonding force inside the adhesive and can have a high glass transition temperature, thus ensuring thermal stability. There are advantages that can be done.

  On the other hand, the hydroxyl value means the number of mg of potassium hydroxide (KOH) necessary for neutralizing acetic acid bound to a hydroxyl group when acetylating 1 g of a sample, and the measuring method is particularly limited. Not. For example, the hydroxyl value in the sample can be calculated by the following formula (1).

  Formula (1): (KOH molecular weight × number of —OH in sample × 1000) / sample molecular weight

  Meanwhile, the protective layer may be formed by a method well known in the art. For example, the radical curable composition may be applied to at least one surface of a polarizer to form a protective layer and then cured. At this time, the application may be performed by an application method well known in the art, for example, spin coating, bar coating, roll coating, gravure coating, blade coating, or the like.

On the other hand, the curing may be performed by photocuring, more specifically, irradiation with active energy rays such as ultraviolet rays, visible rays, electron beams, and X-rays. For example, it can be performed by a method of irradiating ultraviolet rays of about 10 to 2500 mJ / cm ² using an ultraviolet irradiation device.

  Alternatively, the curing may be performed by thermal curing, more specifically, thermal curing at a curing temperature of 80 ° C. or higher. At this time, if necessary, a known amine-based initiator can be additionally added to the composition in order to increase the curing rate during thermal curing.

  Alternatively, the curing may be performed by additionally performing thermosetting after the photocuring, or may be performed by additionally performing photocuring after the thermal curing.

A. While the first compound, the curable composition of the present invention preferably comprises a first compound of the radical polymerizable containing at least two hydroxy groups in the molecule. At this time, the radically polymerizable first compound has at least two hydroxy groups in the molecule, so that it can realize excellent adhesive force due to the hydrogen bond with the polarizer. The hydrogen value can be increased, and at least one radical-polymerizable group in the molecule, for example, an unsaturated bond between carbon atoms, can be used as long as radical polymerization is possible. It can be used without any problems.

  On the other hand, the first radical polymerizable compound preferably includes a (meth) acryloyl group as the radical polymerizable group. This is because radical polymerization is possible as a better one. Here, the (meth) acryloyl group means a radical polymerizable group represented by the following chemical formula A.

  In the chemical formula A, X is hydrogen or methyl, and in *, it is connected to other atoms in the radical polymerizable first compound, for example, carbon, oxygen, sulfur, nitrogen and the like.

  More specifically, in the present invention, the radical polymerizable first compound is not limited to this, but is selected from the group consisting of compounds represented by the following chemical formulas 1 to 17. It can be more than a seed.

  On the other hand, the radical polymerizable first compound of the present invention preferably contains a radical initiator described later at the time of UV curing. However, the first radical polymerizable compound of the present invention may be capable of thermosetting, and in this case, the radical curable composition containing the same can be cured by thermosetting. The photo radical initiator is not required, and there is an advantage that a thermally more stable protective layer can be formed.

B. On the other hand, the second compound, radical initiator, on the other hand, the radical curable composition of the present invention further improves the adhesion between the polarizer and the protective layer, promotes radical polymerizability and further improves the curing rate. In addition, it may further include a radical polymerizable second compound containing at least one hydrophilic functional group in the molecule and a radical initiator. That is, the radical curable composition of the present invention comprises (A) a radical polymerizable first compound containing at least two hydroxy groups in the molecule, and (B) a radical containing at least one hydrophilic functional group in the molecule. It may contain a polymerizable second compound and (C) a radical initiator.

  At this time, the radical polymerizable second compound containing at least one hydrophilic functional group in the molecule (B) has at least one hydrophilic functional group in the molecule, so that it adheres to the polarizer by hydrogen bonding. As long as radical polymerization is possible due to the presence of an unsaturated carbon-carbon double bond in the molecule, it can be used without any particular limitation. However, in this specification, the radical polymerizable second compound containing at least one hydrophilic functional group in the molecule excludes the radical polymerizable first compound containing at least two hydroxy groups in the molecule. Means.

  On the other hand, the hydrophilic functional group is preferably a hydroxy group in order to achieve excellent adhesion and a high hydroxyl value. For example, in the present invention, the radical polymerizable second compound (B) containing at least one hydrophilic functional group in the molecule is not limited to this, but is a compound represented by the following chemical formula I: It is preferable that

In Formula I, R ₁ is an ester group or an ether group; R ₂ is a C _1-10 alkyl group, a C _4-10 cycloalkyl group, or a combination thereof, wherein R ₂ Has one hydroxy substituent in the molecule; R ₃ is hydrogen or a substituted or unsubstituted C _1-10 alkyl group.

In this case, in R ₂ , the alkyl group means a linear or branched hydrocarbon moiety having 1 to 10, or 1 to 8, or 1 to 4 carbon atoms. In the above, the alkyl group may contain at least one unsaturated bond in the molecule. On the other hand, examples of the alkyl group include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, and the like.

In the R ₂ , the cycloalkyl group has a non-aromatic monocyclic, bicyclic or tricyclic hydrocarbon moiety of 4 to 14, or 4 to 10, or 4 to 6 ring carbons. In the present specification, the cycloalkyl group may include at least one unsaturated bond in the molecule. On the other hand, examples of the cycloalkyl group include, but are not limited to, a cyclopentane ring and a cyclohexane ring.

  On the other hand, the hydroxy group may be substituted at any position in the alkyl group or cycloalkyl group. For example, the hydroxy group may be at the end of the alkyl group or may be in the middle of the alkyl group. On the other hand, the remaining hydrogen atoms contained in the alkyl group or cycloalkyl group may be substituted with an arbitrary substituent.

In the above R ₃ , the alkyl group means a linear or branched hydrocarbon moiety having 1 to 10, or 1 to 8, or 1 to 4 carbon atoms. The alkyl group may contain at least one unsaturated bond in the molecule. On the other hand, examples of the alkyl group include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, and the like. One or more hydrogen atoms contained in the alkyl group may be substituted with any substituent.

  More specifically, the compound represented by the chemical formula I is not limited thereto, but may be one or more compounds selected from the compounds represented by the following chemical formulas 18 to 23, for example. It may be.

  The (C) radical initiator is for accelerating radical polymerizability to improve the curing rate, and as the radical initiator, radical initiators generally used in the art can be used. Can be used without limitation.

  More specifically, the radical initiator is, for example, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone. (2-Hydroxy-2-methyl-1-phenyl-1-propanone), 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone (2-Hydroxy-1- [4- (2-hydroxyethyl) phenyl] -2-methyl-1-propanone), methylbenzoylformate, oxy-phenyl-acetic acid-2- [2-oxo-2-phenyl-acetoxy-e Xoxy] -ethyl ester (oxy-phenyl-acetic acid-2- [2oxo-2phenyl-acetoxy-ethyester] -ethyl ester), oxy-phenyl-acetic acid-2- [2-hydroxy-ethoxy] -ethyl ester (oxy- phenyl-acetic acid-2- [2-hydroxy-ethyoxy] -ethyl ester), alpha-dimethoxy-alpha-phenylacetophenone, 2-benzyl-2- (dimethylamino) 1- [ 4- (4-morpholinyl) phenyl] -1-butanone (2-Benzyl-2- (dimethylylamino) -1- [4- (4-morpholin) yl) phenyl] -1-butaneone), 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone (2-Methyl-1- [4- (methylthio) phenyl) ] -2- (4-morpholinyl) -1-propanone), diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide (Diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide), phosphine oxide ), Phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide)), phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide). It may be one or more selected from the group. In particular, in the present invention, phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide (phenylbis (2,4,6-trimethylbenzoyl) -phosphineoxide) can be preferably used.

  On the other hand, the radical curable composition of the present invention is (A) 5 to 90 parts by weight of the first radical polymerizable compound containing at least two hydroxy groups in the molecule with respect to 100 parts by weight of the radical curable composition. More preferably (B) 5 to 90 parts by weight of a radically polymerizable second compound containing at least one hydrophilic functional group in the molecule; and (C) 0.5 to 20 parts by weight of a radical initiator.

  More specifically, the (A) radical polymerizable first compound containing at least two hydroxy groups in the molecule is about 10 to 90 parts by weight, preferably 100 parts by weight of the whole radical curable composition. May be about 10 to 80 parts by weight, more preferably about 20 to 80 parts by weight. When the compound (A) satisfies the above content, all excellent adhesion and water resistance can be ensured.

  The (B) radical polymerizable second compound containing at least one hydrophilic functional group in the molecule is about 5 to 90 parts by weight, preferably 5 parts per 100 parts by weight of the whole radical curable composition. It may be about -80 parts by weight, more preferably about 10-80 parts by weight. When the said (B) compound satisfies the said content, it can have the outstanding adhesiveness.

  Further, the (C) radical initiator is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, and more preferably 0.5 parts by weight with respect to 100 parts by weight of the whole radical curable composition. It may be about -10 parts by weight. This is because when the content of the radical initiator satisfies the above numerical range, the radical curable composition can be cured smoothly.

C. Additional composition for improving water resistance 1
On the other hand, the radical curable composition of the present invention is further improved in order to increase the degree of crosslinking in the protective layer to improve water resistance and to exhibit stable physical properties even in a high humidity environment. D) a polyfunctional (meth) acrylic compound and / or (E) a phosphate compound containing at least one (meth) acrylic group in the molecule.

  For example, the radical curable composition of the present invention includes (A) a radical polymerizable first compound containing at least two hydroxy groups in the molecule; (C) a radical initiator; (D) a polyfunctional (meth). It may contain an acrylic compound and / or a phosphate compound containing (E) at least one (meth) acryl group in the molecule.

  Alternatively, the radical curable composition of the present invention includes (A) a radically polymerizable first compound containing at least two hydroxy groups in the molecule; (B) a radical containing at least one hydrophilic functional group in the molecule. A second polymerizable compound; (C) a radical initiator; (D) a polyfunctional (meth) acrylic compound; and / or (E) a phosphate compound containing at least one (meth) acrylic group in the molecule. It may be a thing.

  At this time, as the (D) polyfunctional (meth) acrylic compound, various polyfunctional (meth) acrylic compounds widely known in the art can be used without any particular limitation. However, in this specification, except for the polyfunctional (meth) acrylic compounds listed as examples below, there are many compounds corresponding to the above-mentioned (A) to (B) compounds and the (E) compounds described later. Excluded from functional (meth) acrylic compounds.

  For example, in the present invention, the (D) polyfunctional (meth) acrylic compound includes ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di ( (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol di ( (Meth) acrylate, ditrimethylolpropane di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate Polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, silicon di (meth) acrylate, hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, 2, 2-bis [4- (meth) acryloyloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxyethoxyethoxycyclohexyl] propane, hydrogenated dicyclopentadienyl di (meth) acrylate, tri Cyclodecane dimethanol di (meth) acrylate, 1,3-dioxane-2,5-diyldi (meth) acrylate, 2- (2-hydroxy-1,1-dimethylethyl) -5-ethyl-5-hydroxymethyl 1,3-dioxane di (meth) acrylate, tris (hydroxyethyl) isocyanurate di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, Ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) An acrylate etc. are mentioned. These can be used alone or in combination.

  On the other hand, although not limited thereto, the (D) polyfunctional (meth) acrylic compound is one or more selected from the group consisting of compounds represented by the following chemical formulas II to IV. More preferably. This is because the effect of improving water resistance is more excellent in this case.

In Formula II, R ₄ and R ₅ are each independently a (meth) acryloyloxy group or a (meth) acryloyloxyalkyl group.

In this case, in R ₄ and R ₅ , the alkyl of the (meth) acryloyloxyalkyl group is a linear or branched chain of 1 to 10, or 1 to 8, or 1 to 4 carbon atoms. This means a hydrocarbon moiety, and the (meth) acryloyloxy group may be substituted at any position of the alkyl group. The remaining one or more hydrogen atoms contained in the alkyl may be substituted with any substituent.

In Formula III, R ₆ , R ₇ and R ₈ are each independently a (meth) acryloyloxy group or a (meth) acryloyloxyalkyl group, and R ₉ is a (meth) acryloyloxy group, (meta ) An acryloyloxyalkyl group, a hydroxy group, or a substituted or unsubstituted C _1-10 alkyl group.

At this time, in R ₆ , R ₇ , R ₈ and R ₉ , the alkyl of the (meth) acryloyloxyalkyl group is 1 to 10, or 1 to 8, or 1 to 4 carbon atoms. This means a chain or branched hydrocarbon moiety, and the (meth) acryloyloxy group may be substituted at any position of the alkyl group. The remaining one or more hydrogen atoms contained in the alkyl may be substituted with any substituent.

In the R ₉ , the alkyl group means a linear or branched hydrocarbon moiety having 1 to 10, or 1 to 8, or 1 to 4 carbon atoms, and the alkyl group includes One or more hydrogen atoms contained may be substituted with any substituent.

In Formula IV, R ₁₀ is a substituted or unsubstituted C _1-10 alkylene, and R ₁₁ and R ₁₂ are each independently a (meth) acryloyloxy group or a (meth) acryloyloxyalkyl group. is there.

In this case, in R ₁₀ , the alkylene means a linear or branched divalent hydrocarbon moiety having 1 to 10, or 1 to 8, or 1 to 6 carbon atoms, In the specification, the alkylene group may contain at least one unsaturated bond in the molecule. On the other hand, examples of the alkylene group include, but are not limited to, methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, nonamethylene, decamethylene, and the like. One or more hydrogen atoms contained in the alkylene may be substituted with any substituent.

In the R ₁₁ and R ₁₂ , the alkyl of the (meth) acryloyloxyalkyl group is a straight chain or branched carbon of 1 to 10, or 1 to 8, or 1 to 4 carbon atoms. This means a hydrogen moiety, and the (meth) acryloyloxy group may be substituted at any position of the alkyl group. The remaining one or more hydrogen atoms contained in the alkyl may be substituted with any substituent.

  More specifically, the (D) polyfunctional (meth) acrylic compound is not limited to this, but is selected from the group consisting of compounds represented by the following chemical formulas 24 to 27. It may be one or more compounds.

  The phosphate compound containing at least one (meth) acryl group in the molecule (E) can be used without any particular limitation as long as it is a phosphate compound containing at least one (meth) acryl group in the molecule. . For example, although not limited thereto, the phosphate compound containing at least one (meth) acryl group in the (E) molecule may be a compound represented by the following chemical formula V.

In Formula V, R ₁₃ is a substituted or unsubstituted C _1-10 alkylene group, a substituted or unsubstituted C _4-14 cycloalkylene group, a substituted or unsubstituted C _6-14 arylene group, or R ₁₄ is hydrogen or a methyl group; n is an integer of 0 to 2, m is an integer of 1 to 3, and n + m = 3.

In this case, in R ₁₃ , the alkylene group means a linear or branched divalent hydrocarbon moiety of 1 to 10, or 1 to 8, or 1 to 4 carbon atoms, In the present specification, the alkylene group may include at least one unsaturated bond in the molecule. On the other hand, examples of the alkylene group include, but are not limited to, methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, nonamethylene, decamethylene, and the like. One or more hydrogen atoms contained in the alkylene group may be substituted with any substituent.

In the R ₁₃ , the cycloalkylene group is a non-aromatic divalent monocyclic, bicyclic or tricyclic of 4 to 14, 4 to 10 or 4 to 6 ring carbons. It means a hydrocarbon moiety, and in the present specification, the alkylene group may contain at least one unsaturated bond in the molecule. On the other hand, examples of the cycloalkylene group include, but are not limited to, a divalent cyclopentane ring and a cyclohexane ring. One or more hydrogen atoms contained in the cycloalkylene group may be substituted with any substituent.

Further, in R ₁₃ , the arylene group means a divalent monocyclic, bicyclic or tricyclic aromatic hydrocarbon moiety having 6 to 14 or 6 to 12 ring atoms, Although not limited to, a bivalent benzene ring, a naphthalene ring, an anthracene ring, a biphenyl ring, etc. can be mentioned as an example. One or more hydrogen atoms contained in the arylene group may be substituted with any substituent.

On the other hand, R ₁₃ is not limited to this, but is preferably a substituted or unsubstituted C _1-10 alkylene group, and is preferably a substituted or unsubstituted C _1-8 alkylene group. More preferably, it is a substituted or unsubstituted C _1-4 alkylene group.

  Moreover, in said n and m, n is an integer of 1-2, m is an integer of 1-2, and it is more preferable that it is n + m = 3, said n is 2, m is 1, and n + m = 3 is particularly preferred.

  More specifically, the phosphate compound containing at least one (meth) acryl group in the (E) molecule is not limited to this, but from the compounds represented by the following chemical formulas 28 to 33: One or more compounds selected from the group consisting of:

  On the other hand, when the radically curable composition of the present invention further contains the compound (D) and / or the compound (E) as described above, the radically polymerizable second composition containing at least two hydroxy groups in the molecule (A). The content of one compound may be about 10 to 90 parts by weight, preferably about 10 to 80 parts by weight, and more preferably about 20 to 80 parts by weight with respect to 100 parts by weight of the entire radical curable composition. When the compound (A) satisfies the content, all of excellent adhesion and high glass transition temperature can be ensured.

  Further, the content of the radically polymerizable second compound containing at least one hydrophilic functional group in the molecule (B) is about 5 to 90 parts by weight with respect to 100 parts by weight of the whole radical curable composition, Preferably it may be about 5 to 80 parts by weight, more preferably about 10 to 80 parts by weight. When the said (B) compound satisfies the said content, it can have the outstanding adhesiveness.

  Furthermore, the content of the radical initiator (C) is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, more preferably 100 parts by weight of the whole radical curable composition. It may be about 0.5 to 10 parts by weight. This is because the curing of the adhesive can be carried out smoothly when the content of the radical initiator satisfies the numerical range.

  Further, the content of the (D) polyfunctional (meth) acrylic compound is about 4 to 50 parts by weight, preferably about 5 to 40 parts by weight, with respect to 100 parts by weight of the whole radical curable composition. Preferably, it may be about 6 to 40 parts by weight. When the compound (D) satisfies the content range, the radical curable composition of the present invention can ensure excellent adhesion and water resistance.

  Furthermore, the content of the phosphate compound having at least one (meth) acryloyloxy group in the (E) molecule is preferably about 0.5 to 30 parts by weight with respect to 100 parts by weight of the entire radical curable composition. May be about 0.5 to 20, more preferably about 0.5 to 15. When the said (E) compound satisfies the said content range, the radical curable composition of this invention can ensure the outstanding adhesiveness and water resistance.

  For example, in the radical curable composition, 100 parts by weight of the radical curable composition (A) 5 to 90 parts by weight of the first radical polymerizable compound containing at least two hydroxy groups in the molecule; ) 5-90 parts by weight of a radically polymerizable second compound containing at least one hydrophilic functional group in the molecule; (C) 0.5-20 parts by weight of a radical initiator; (D) polyfunctional (meth) acrylic 4 to 50 parts by weight of the system compound; and / or (E) 0.5 to 30 parts by weight of a phosphate compound containing at least one (meth) acryl group in the molecule may be included.

D. Additional composition for improving water resistance 2
On the other hand, the radical curable composition of the present invention is additionally provided with (F) at least one epoxy group in the molecule in order to improve water resistance and exhibit stable physical properties even in a high humidity environment. And (G) a cationic initiator.

  For example, the radical curable composition of the present invention comprises (A) a radical polymerizable first compound containing at least two hydroxy groups in the molecule; (F) an epoxy compound containing at least one epoxy group in the molecule; And (G) a cationic initiator.

  Alternatively, the radical curable composition of the present invention includes (A) a radically polymerizable first compound containing at least two hydroxy groups in the molecule; (B) a radical containing at least one hydrophilic functional group in the molecule. A polymerizable second compound; (C) a radical initiator; (F) an epoxy compound containing at least one epoxy group in the molecule; and (G) a cationic initiator.

  At this time, the epoxy compound having at least one epoxy group in the molecule (F) is not particularly limited as long as it has at least one epoxy group in the molecule. For example, an aromatic epoxy compound , Hydrogenated epoxy compounds, alicyclic epoxy compounds, epoxy group-containing (meth) acrylic compounds, and the like. These can be used individually or in mixture of 2 or more.

  At this time, the aromatic epoxy compound means an epoxy compound containing at least one aromatic hydrocarbon ring in the molecule, but is not limited thereto, for example, diglycidyl ether of bisphenol A, Bisphenol type epoxy resins such as diglycidyl ether of bisphenol F and diglycidyl ether of bisphenol S; novolac type epoxy resins such as phenol novolac epoxy resin, cresol novolac epoxy resin, hydroxybenzaldehyde phenol novolac epoxy resin; tetrahydroxyphenylmethane And glycidyl ethers of tetrahydroxybenzophenone, polyfunctional epoxy resins such as epoxidized polyvinylphenol, and the like.

  The hydrogenated epoxy compound means an epoxy compound obtained by selectively hydrogenating the aromatic epoxy compound under pressure in the presence of a catalyst.

  Furthermore, the alicyclic epoxy compound means an epoxy compound in which an epoxy group is formed between two adjacent carbon atoms constituting an aliphatic hydrocarbon ring, and is not limited thereto. Are, for example, 2- (3,4-epoxy) cyclohexyl-5,5-spiro- (3,4-epoxy) cyclohexane-m-dioxane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, vinylcyclohexanedioxide, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy -6-methylcyclohexylmethyl) adipate, exo-exobis (2 3-epoxycyclopentyl) ether, endo-exobis (2,3-epoxycyclopentyl) ether, 2,2-bis [4- (2,3-epoxypropoxy) cyclohexyl] propane, 2,6-bis (2,3- Epoxypropoxycyclohexyl-p-dioxane), 2,6-bis (2,3-epoxypropoxy) norbornene, limonene dioxide, 2,2-bis (3,4-epoxycyclohexyl) propane, dicyclopentadiene dioxide, 1 , 2-epoxy-6- (2,3-epoxypropoxy) hexahydro-4,7-methanoindane, p- (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether, 1- (2,3- Epoxypropoxy) phenyl-5,6-epoxyhexahydro-4 7-methanoindane, o- (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether), 1,2-bis [5- (1,2-epoxy) -4,7-hexahydromethanoindano Xyl] ethanecyclopentenylphenylglycidyl ether, methylenebis (3,4-epoxycyclohexane) ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), and the like.

  The epoxy group-containing (meth) acrylic compound means a compound containing all epoxy groups and (meth) acryloyloxy groups in the molecule, and is not limited thereto. For example, glycidyl acrylate, 2 -Methyl glycidyl acrylate, 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, 3,4-epoxycyclohexyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl methacrylate, 6,7- Examples thereof include epoxy heptyl methacrylate, 3,4-epoxycyclohexyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether.

  On the other hand, the epoxy compound having at least one epoxy group in the molecule (F) preferably contains one or more selected from the group consisting of alicyclic epoxy compounds and epoxy group-containing (meth) acrylic compounds. . At this time, the alicyclic epoxy compound is an epoxy compound having at least two epoxy groups and at least two alicyclic rings in the molecule, for example, 3,4-epoxycyclohexylmethyl-3,4- Epoxycyclohexanecarboxylate is particularly preferable, and the epoxy group-containing (meth) acrylic compound is particularly preferably a glycidyl (meth) acrylic compound such as glycidyl acrylate or glycidyl methacrylate. In this case, the effect of improving the water resistance of the protective layer of the present invention is extremely excellent.

  The (G) cation initiator is a compound that generates an acid (H +) by active energy rays, and the cation initiator usable in the present invention is, for example, a sulfonium salt or an iodonium salt. Those containing (Iodonium salt) are preferred. Specific examples of the photoacid generator containing a sulfonium salt or an iodonium salt include, for example, diphenyl (4-phenylthio) phenylsulfonium hexafluoroantimonate (Diphenyl (4-phenylthio) phenylsulfonium). hexafluoroantimonate), diphenyl (4-phenylthio) phenylsulfonium hexafluorophosphate (Diphenyl (4-phenylthio) phenylsulfophosphate hexylphosphate), (phenyl) [4- (2-methylpropyl) phenyl] -iodonium hexafluorophosphate ((4phenyl)) -(2-met ylpropyl) phenyl] -iodonium hexafluorophosphate), (thiodi-4,1-phenylene) bis (diphenylsulfonium) dihexafluoroantimonate ((Thiodi-4,1-phenylene) bis (diphenylsulfonium) dihexafluoroantimony-4 , 1-phenylene) bis (diphenylsulfonium) dihexafluorophosphate ((Thiodi-4,1-phenylene) bis (diphenylsulfonium) dihexafluorophosphate). It is not a thing.

  On the other hand, when the radical curable composition of the present invention further comprises (F) a compound and (G) a cation initiator as described above, (A) a radical polymerizable compound containing at least two hydroxy groups in the molecule. The content of the first compound may be about 10 to 90 parts by weight, preferably about 10 to 80 parts by weight, and more preferably about 20 to 80 parts by weight with respect to 100 parts by weight of the entire radical curable composition. . When the compound (A) satisfies the content, all of excellent adhesion and high glass transition temperature can be ensured.

  Further, the content of the radically polymerizable second compound containing at least one hydrophilic functional group in the molecule (B) is about 5 to 90 parts by weight with respect to 100 parts by weight of the whole radical curable composition, Preferably it may be about 5 to 80 parts by weight, more preferably about 10 to 80 parts by weight. When the compound (B) satisfies the above content, the radically curable composition of the present invention can have particularly excellent adhesion.

  Furthermore, the content of the radical initiator (C) is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, more preferably 100 parts by weight of the whole radical curable composition. It may be about 0.5 to 10 parts by weight. When the content of the radical initiator satisfies the above numerical range, the adhesive can be cured smoothly.

  In addition, the content of the epoxy compound having at least one epoxy group in the molecule (F) is about 1 to 30 parts by weight, preferably 4 to 25 parts by weight with respect to 100 parts by weight of the entire radical curable composition. The degree may be about 5 to 20 parts by weight, more preferably. When the said (F) compound satisfies the said content range, the adhesiveness and water resistance which were excellent in the radical curable composition of this invention can be ensured.

  Furthermore, the content of the cation initiator (G) is about 0.5 to 15 parts by weight, preferably about 0.5 to 12 parts by weight, more preferably 100 parts by weight of the whole radical curable composition. May be about 0.5 to 10 parts by weight. When the cation initiator satisfies the above content range, the adhesive can be cured smoothly.

  For example, in the radical curable composition, 100 parts by weight of the radical curable composition (A) 5 to 90 parts by weight of the first radical polymerizable compound containing at least two hydroxy groups in the molecule; ) 5 to 90 parts by weight of a radically polymerizable second compound containing at least one hydrophilic functional group in the molecule; (C) 0.5 to 20 parts by weight of a radical initiator; (F) at least one epoxy in the molecule 1 to 30 parts by weight of an epoxy compound containing a group; and (G) 0.5 to 15 parts by weight of a cationic initiator.

E. Properties whereas the curable composition, the curable composition preferably has a glass transition temperature after curing is 50 ° C. or higher. For example, it may be 55 to 200 ° C or 60 to 200 ° C. In this case, the protective layer to be formed is thermally stable and the polarizing plate including the protective layer is excellent in heat resistance.

  Moreover, it is preferable that the thickness of the protective layer formed using the said radical curable composition is 0.5-20 micrometers, for example, may be 0.5-15 micrometers or 0.5-10 micrometers. This is because, when the thickness of the protective layer satisfies the above range, the manufactured polarizing plate can be thin and light. If the thickness is too thin, the thermal shock stability and curl characteristics of the polarizer are fragile. If it is too thick, it is difficult to make the polarizing plate thin.

1-3. Protective films on the other hand, the polarizing plate of the present invention may optionally include a protective film on one surface of the polarizer may further comprise a. More specifically, in the polarizing plate of the present invention, when the protective layer is formed on one surface of the polarizer, in order to support and protect the polarizer on the surface opposite to the surface on which the protective layer is formed, Another protective film can be attached via the adhesive layer.

  At this time, the protective film is for supporting and protecting the polarizer, and protective films of various materials generally known in the art, for example, a cellulose-based film, polyethylene terephthalate (PET, Polyethylene terephthalate film, cycloolefin polymer (COP) film, acrylic film and the like can be used without limitation. Among these, it is particularly preferable to use an acrylic film when considering optical characteristics, durability, economy, and the like.

  On the other hand, the acrylic film that can be used in the present invention can be obtained by molding a molding material containing a (meth) acrylate resin as a main component by extrusion molding. At this time, the (meth) acrylate-based resin is mainly composed of a resin containing a (meth) acrylate-based unit, and not only a homopolymer resin composed of a (meth) acrylate-based unit but also a (meth) acrylate-based unit. In addition to this, it is a concept including a copolymer resin in which other monomer units are copolymerized and a blend resin in which another resin is blended with the (meth) acrylate resin as described above.

  On the other hand, the (meth) acrylate unit may be, for example, an alkyl (meth) acrylate unit. Here, the alkyl (meth) acrylate unit means all alkyl acrylate units and alkyl methacrylate units, and the alkyl group of the alkyl (meth) acrylate unit has 1 to 10 carbon atoms. It is more preferable that it is C1-C4.

  Examples of the monomer unit that can be copolymerized with the (meth) acrylate unit include a styrene unit, a maleic anhydride unit, and a maleimide unit. At this time, the styrene-based unit is not limited thereto, but styrene, α-methylstyrene, and the like can be given as examples; the maleic anhydride-based monomer is limited thereto. Examples of the maleimide monomer include, but are not limited to, maleic anhydride, methylmaleic anhydride, cyclohexylmaleic anhydride, phenylmaleic anhydride, and the like. Although not mentioned, maleimide, N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and the like can be mentioned as examples. These can be used alone or in combination.

  On the other hand, the acrylic film may be a film containing a (meth) acrylate resin having a lactone ring structure. Specific examples of the (meth) acrylate resin having a lactone ring structure include, for example, Japanese Patent Publication No. 2000-230016, Japanese Patent Publication No. 2001-151814, and Japanese Patent Publication No. 2002-120326. (Meth) acrylate resins having a lactone ring structure described in No.

  The method for producing the acrylic film is not particularly limited. For example, a (meth) acrylate resin and other polymers, additives, and the like are sufficiently mixed by any appropriate mixing method to obtain a thermoplastic resin composition. After production, this is formed into a film, or (meth) acrylate resin and other polymers, additives, etc. are produced in separate solutions and then mixed to form a uniform mixture. Later, this can be formed into a film. The acrylic film may be either an unstretched film or a stretched film. In the case of a stretched film, it may be a uniaxially stretched film or a biaxially stretched film, and in the case of a biaxially stretched film, it may be either a simultaneous biaxially stretched film or a sequential biaxially stretched film.

  Meanwhile, the polarizing plate of the present invention may further include a primer layer between the adhesive layer and the protective film in order to further improve the adhesive force. At this time, the primer layer is formed by applying a coating liquid containing a water-dispersible polymer resin, water-dispersible fine particles, and water on a protective film using a bar coating method, a gravure coating method, or the like, and then drying. May be formed. The water-dispersible polymer resin may be, for example, a water-dispersed polyurethane resin, a water-dispersed acrylic resin, a water-dispersed polyester resin, or a combination thereof, and the water-dispersible fine particles are silica, titania, alumina, and the like. Inorganic fine particles such as zirconia, organic fine particles composed of silicone resin, fluorine resin, (meth) acrylic resin, cross-linked polyvinyl alcohol, and melamine resin, or combinations thereof can be used. It is not limited to.

  On the other hand, the polarizer and the protective film are adhered by coating the surface of the polarizer or the protective film with an adhesive using a roll coater, gravure coater, bar coater, knife coater, or capillary coater, and then combining them. It may be carried out by a method of performing heat interleaving with a paper roll, pressing at room temperature and interleaving, or a method of performing UV irradiation after interleaving. On the other hand, as the adhesive, various polarizing plate adhesives used in the technical field, such as polyvinyl alcohol adhesives, polyurethane adhesives, acrylic adhesives, cationic adhesives, radical adhesives, etc. Can be used without limitation.

1-4. While the adhesive layer, the polarizing plate of the present invention, for attachment of the optical film, such as a display device panel or the retardation film, can optionally include an adhesive layer on the protective layer.

  At this time, the pressure-sensitive adhesive layer may be formed using various pressure-sensitive adhesives well known in the art, and the type thereof is not particularly limited. For example, the adhesive layer may be a rubber adhesive, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl alcohol adhesive, a polyvinylpyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, It may be formed using a vinyl alkyl ether pressure sensitive adhesive or the like. Among them, it is particularly preferable to use an acrylic pressure-sensitive adhesive when considering transparency and heat resistance.

  Meanwhile, the pressure-sensitive adhesive layer may be formed by applying a pressure-sensitive adhesive on the upper part of the protective layer. After the pressure-sensitive adhesive is applied on the release sheet, the pressure-sensitive adhesive sheet produced by drying is applied to the upper part of the protective layer. It may be formed by a method of attaching to the substrate.

2. Image Display Device The polarizing plate of the present invention as described above can be usefully applied to an image display device such as a liquid crystal display device. The image display device may be, for example, a liquid crystal display device including a liquid crystal panel and polarizing plates respectively provided on both surfaces of the liquid crystal panel. At this time, at least one of the polarizing plates is the present invention. It may be the polarizing plate concerning. At this time, the type of the liquid crystal panel included in the liquid crystal display device is not particularly limited. For example, it is not limited to the type, but a passive matrix panel such as a TN (twisted nematic) type, STN (super twisted nematic) type, F (ferroelectric) type, or PD (polymer dispersed) type; two-terminal type ( Active matrix type panels such as two terminal or three terminal; all known panels such as lateral electric field (IPS) panels and vertical alignment (VA) panels are all applicable Is possible. Further, other configurations constituting the liquid crystal display device, for example, the types of the upper and lower substrates (ex. Color filter substrate or array substrate) are not particularly limited, and configurations known in this field can be employed without limitation. .

  Hereinafter, the present invention will be described in more detail through specific examples.

Production Example 1-Production of Acrylic Protective Film Poly (N-cyclohexylmaleimide-co-methyl methacrylate), styrene-maleic anhydride copolymer resin, and phenoxy resin were uniformly used in a weight ratio of 100: 2.5: 5. The resin composition mixed in was supplied to a 24φ extruder substituted with nitrogen from the raw material hopper to the extruder and melted at 250 ° C. to produce raw pellets.

  As the phenoxy resin, PKFE (Mw = 60,000, Mn = 16,000, Tg = 95 ° C.) of InChemRez was used, and the styrene-maleic anhydride copolymer resin was 85% by weight of styrene, maleic anhydride. As a result of NMR analysis, poly (N-cyclohexylmaleimide-co-methyl methacrylate) resin having a content of N-cyclohexylmaleimide of 6.5% by weight was used.

  The obtained raw material pellets are vacuum dried, melted at 260 ° C. with an extruder, passed through a coat hanger type T-die, passed through a chrome plating casting roll, a drying roll, etc., to form a film having a thickness of 150 μm. Manufactured. The film was stretched at a rate of 170% in the MD direction using a roll speed difference at 125 ° C. using a pilot stretching equipment to produce an acrylic film.

  After the corona treatment of the acrylic film produced through the above process, the solid content of 10 produced by diluting CK-PUD-F (Chokuwang urethane dispersion) with pure water on one surface of the acrylic film. A primer composition obtained by adding 20 parts by weight of an oxazoline cross-linking agent (Nippon Shokubai Co., Ltd., WS700) to a primer composition of wt% was coated with # 7 bar, and then a tenter was applied at 130 ° C. in the TD direction. The resulting film was 190% stretched to finally produce an acrylic protective film having a primer layer thickness of 400 nm.

Production Example 2 Production of Radical Curable Composition (1) Radical Curable Composition A
To 100 parts by weight of a resin composition produced by adding 100% by weight of GLA (glyceryl monoacrylate), 3 parts by weight of radical initiator irgacure-819 (Ciba) was added to obtain radical curable composition A for polarizing plate. Manufactured.

(2) Radical curable composition B
3 parts by weight of irgacure-819 (Ciba) as a radical initiator was added to 100 parts by weight of a resin composition produced by adding 80% by weight of GLA (glyceryl monoacrylate) and 20% by weight of HEA (hydroxyethyl acrylate). A radical curable composition B for plates was produced.

(3) Radical curable composition C
3 parts by weight of irgacure-819 (Ciba) as a radical initiator was added to 100 parts by weight of a resin composition prepared by adding 80% by weight of GLM (glyceryl mono-methacrylate) and 20% by weight of HEA (hydroxyethyl acrylate). A radical curable composition C for polarizing plates was produced.

(4) Radical curable composition D
3 parts by weight of irgacure-819 (Ciba), a radical initiator, was added to 100 parts by weight of a resin composition produced by adding 80% by weight of GLA (glyceryl monoacrylate) and 20% by weight of 1,4-cyclohexanedimethanol mono-acrylate. A radical curable composition D for polarizing plate was produced.

(5) Radical curable composition E
To 100 parts by weight of a resin composition produced by adding 100% by weight of HEA (hydroxyethyl acrylate), 3 parts by weight of radical initiator irgacure-819 (Ciba) was added to obtain radical curable composition E for polarizing plate. Manufactured.

(6) Radical curable composition F
To 100 parts by weight of a resin composition produced by adding 100% by weight of HEAA (hydroxyethyl acrylamide), 3 parts by weight of radical initiator irgacure-819 (Ciba) was added to obtain radical curable composition F for polarizing plate F. Manufactured.

Comparative Example 3
After applying the radical curable composition A with a dropper to the primer layer of the acrylic film-based protective film produced in Production Example 1 and laminating it on one surface of the polarizer (PVA element), the final adhesive layer has a thickness of 1 to 1. After setting the conditions to be 2 μm, a laminator (5 m / min) was passed. Thereafter, the surface on which the acrylic film was laminated was irradiated with 1000 mJ / cm ² of ultraviolet rays using a UV irradiation apparatus (Metal halide lamp) to produce a polarizing plate having a protective film on one surface of the polarizer.

Next, after applying the radical curable composition A to the other surface of the polarizing plate on which the polarizer protective film is laminated, and laminating a PET film having a releasing force, the thickness of the final protective layer After setting the conditions so that the thickness was 4 to 5 μm, a laminator (5 m / min) was passed. Thereafter, the surface on which the release PET is laminated is irradiated with 1000 mJ / cm ² of ultraviolet rays using an ultraviolet irradiation device (Metal halide lamp), the PET film is removed, and a protective film is provided on one surface of the polarizer. A polarizing plate having a protective layer on the other surface was prepared.

Example 2
A polarizing plate was produced in the same manner as in Comparative Example 3 except that B was used as the radical curable composition.

Example 3
A polarizing plate was produced in the same manner as in Comparative Example 3 except that B was used as the radical curable composition, and heat-treated in an oven at 90 ° C. for 1 minute.

Example 4
A polarizing plate was produced in the same manner as in Comparative Example 3 except that C was used as the radical curable composition.

Example 5
A polarizing plate was produced in the same manner as in Comparative Example 3 except that D was used as the radical curable composition.

Comparative Example 1
A polarizing plate was produced in the same manner as in Comparative Example 3 except that E was used as the radical curable composition.

Comparative Example 2
A polarizing plate was produced in the same manner as in Comparative Example 3 except that F was used as the radical curable composition.

Experimental Example 1-Hydroxyl Value The hydroxyl values of the compositions used in Examples 2 to 5 and Comparative Examples 1 to 3 were measured and are shown in Table 1 below. At this time, the hydroxyl value of the composition was calculated using the following formula (1).

Formula (1): (KOH molecular weight × number of —OH in sample × 1000) / sample molecular weight

Experimental Example 2 Evaluation of Adhesion of Protective Layer The adhesion of the protective layer of the polarizing plate produced in Examples 2 to 5 and Comparative Examples 1 to 3 was measured and shown in Table 1 below. Specifically, the radical curable composition used in Examples 2 to 5 and Comparative Examples 1 to 3 is applied on a polarizer (PVA element) at 4 to 5 μm, and a polarizer (PVA element) is applied thereon. After laminating and passing through a laminator, UV light was irradiated at 1000 mJ / cm ² using an ultraviolet irradiation device (Metal halide lamp) to produce a peeling force sample comprising a polarizer / protective layer / polarizer. . The manufactured sample was allowed to stand for 4 days under the conditions of a temperature of 20 ° C. and a humidity of 70%, then cut to a width of 20 mm and a length of 100 mm, and equipped with a Texture Analyzer (TA-XT Plus from Stable Micro Systems) at a speed of 300 m. The peel force was measured at 90 ° / min. At this time, if the peel force is 1.0 N / 2 cm to 2.0 N / 2 cm, it is excellent, if it is 0.5 N / 2 cm or more and less than 1.0 N / 2 cm, it is good, if it is less than 0.5 N / 2 cm, it is bad. displayed.

Experimental Example 3 Evaluation of Thermal Shock Physical Properties The thermal shock physical properties of the polarizing plates produced in Examples 2 to 5 and Comparative Examples 1 to 3 were measured and are shown in Table 1 below. Specifically, the polarizing plates produced in Examples 2 to 5 and Comparative Examples 1 to 3 were laminated on a glass substrate and left at −40 ° C. for 30 minutes. For 30 minutes was repeated 100 times. Then, the presence or absence of the deformation | transformation in the external appearance of a polarizing plate was evaluated with the naked eye. In the appearance of the polarizing plate, the case where cracks of 2 mm or less are generated only at the end portions is excellent, and the case where only short linear cracks of 5 mm or more other than the end portions are confirmed is good. The case where the crack occurred was indicated as inferior.

As is clear from Table 1, in Examples 2 to 5 of the present invention having a hydroxyl value of 500 mg · KOH / g or more, the adhesiveness of the protective layer is excellent even in a wet environment. It can be seen that the thermal shock stability is excellent.

  However, in the case of Comparative Examples 1 and 2 having a hydroxyl value of less than 500 mg · KOH / g, it can be seen that Comparative Example 1 has poor thermal shock stability and the protective layer of Comparative Example 2 has poor adhesion.

  Next, when the radically curable composition of the present invention further includes the (D) compound and (E) compound of the present invention or the (F) compound and (G) a cationic initiator, In order to confirm the effect of improving water resistance, the following experiment was conducted.

Production Example 3 Production of Radical Curable Composition (1) Radical Curable Composition G
GLA (glyceryl monoacrylate) 64.5% by weight, HEA (hydroxyethyl acrylate) 16% by weight, DCPDA (Dimethylol trichlorodiacrylate) 16% by weight, di- (methacryloyl compound) 3.5% by weight A radical curable composition G for polarizing plate was produced by adding 3 parts by weight of radical initiator irgacure-819 (Ciba) to parts by weight.

(2) Radical curable composition H
CPI100P (San 3), a cation initiator, in 100 parts by weight of a resin composition prepared by adding 73% by weight of GLA (glyceryl monoacrylate), 18% by weight of HEA (hydroxyethyl acrylate), and 9% by weight of GMA (glycylyl methacrylate) Part by weight and 3 parts by weight of radical initiator irgacure-819 (Ciba) were added to produce radical curable composition H for polarizing plate.

Example 6
A polarizing plate was produced in the same manner as in Comparative Example 3 except that G was used as the radical curable composition.

Example 7
A polarizing plate was produced in the same manner as in Comparative Example 3 except that H was used as the radical curable composition.

Experimental Example 4 Evaluation of Water Resistance of Polarizing Plate The water resistance of the polarizing plates produced in Examples 6 to 7 was measured and shown in Table 2 below. Specifically, the polarizing plates of Examples 6 to 7 were laminated on a glass substrate, immersed in a thermostatic bath at 60 ° C., and after 8 hours, the end of the polarizing plate was not decolorized. Judgment was made and the case where there was no deformation was indicated as excellent, and the case where decolorization occurred was indicated as poor. On the other hand, the methods for measuring the hydroxyl value, adhesion, and glass transition temperature additionally described in Table 2 below are the same as described above.

  As is clear from Table 2, Example 6 further includes the (D) compound and (E) compound or the (F) compound and (G) cation initiator in the radical curable composition of the present invention. In the case of No. and No. 7, it can be confirmed that the water resistance is also excellent.

  On the other hand, in the case of the said Example, although the adhesive layer and the protective layer were manufactured using the same radical curable composition for convenience at the time of manufacture of a polarizing plate, it is not necessarily restrained by this.

  The embodiment of the present invention has been described in detail above, but the scope of the right of the present invention is not limited to this, and various within the scope of the technical idea of the present invention described in the claims. It will be apparent to those skilled in the art that various modifications and variations are possible.

Claims (15)

A polarizer,
A polarizing plate comprising a protective layer formed on at least one surface of the polarizer,
The protective layer, Ri cured der hydroxyl value (hydroxy value) is 500 mg · KOH / g or more 900 mg · KOH / g or less of curable composition,
The radical curable composition comprises (A) a radical polymerizable first compound containing at least two hydroxy groups in the molecule, and (B) a radical polymerizable second compound containing at least one hydrophilic functional group in the molecule. A compound, and (C) a radical initiator,
The said radically polymerizable 2nd compound is 1 or more types selected from the group which consists of a compound represented by following Chemical formula 18-Chemical formula 23 , The polarizing plate characterized by the above-mentioned.

2. The polarizing plate according to claim 1 , wherein the first radical polymerizable first compound is at least one selected from the group consisting of compounds represented by chemical formulas 1 to 17 below.

The radical curable composition comprises (A) 5 to 90 parts by weight of a radically polymerizable first compound containing at least two hydroxy groups in the molecule with respect to 100 parts by weight of the radical curable composition; at least one second compound 5-90 parts by weight of the radical polymerizable containing a hydrophilic functional group within; characterized in that it comprises a and (C) a radical initiator 0.5 to 20 parts by weight, in claim 1 The polarizing plate as described. The radical curable composition further comprises (D) a polyfunctional (meth) acrylic compound, (E) a phosphate compound containing at least one (meth) acrylic group in the molecule, or a combination thereof. The polarizing plate according to claim 1 . 5. The polarizing plate according to claim 4 , wherein the (D) polyfunctional (meth) acrylic compound is contained in an amount of 4 to 50 parts by weight with respect to 100 parts by weight of the radical curable composition. The phosphate compound containing at least one (meth) acrylic group in the (E) molecule is contained in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the radical curable composition. Item 5. The polarizing plate according to item 4 . The polarizing plate according to claim 1 , wherein the radically curable composition further comprises (F) an epoxy compound having at least one epoxy group in the molecule, and (G) a cationic initiator. Wherein (F) an epoxy compound containing at least one epoxy group in the molecule, with respect to curable compositions 100 parts by weight, and wherein the contained 1 to 30 parts by weight, according to claim 7 Polarizer. The polarizing plate according to claim 7 , wherein the (G) cation initiator is contained in an amount of 0.5 to 15 parts by weight with respect to 100 parts by weight of the radical curable composition.   The polarizing plate according to claim 1, wherein the radical curable composition is cured by photocuring or heat curing.   The polarizing plate according to claim 1, wherein the radical curable composition has a glass transition temperature after curing of 50 ° C. or higher.   The polarizing plate according to claim 1, wherein the protective layer has a thickness of 0.5 to 20 μm.   The polarizing plate according to claim 1, wherein a protective film is attached to an opposite surface of the surface on which the protective layer of the polarizer is formed via an adhesive layer.   The polarizing plate according to claim 1, further comprising an adhesive layer on the protective layer.   An image display device comprising the polarizing plate according to claim 1.